From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263101AbTJJQm1 (ORCPT ); Fri, 10 Oct 2003 12:42:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263106AbTJJQm1 (ORCPT ); Fri, 10 Oct 2003 12:42:27 -0400 Received: from holomorphy.com ([66.224.33.161]:50561 "EHLO holomorphy") by vger.kernel.org with ESMTP id S263101AbTJJQmW (ORCPT ); Fri, 10 Oct 2003 12:42:22 -0400 Date: Fri, 10 Oct 2003 09:44:08 -0700 From: William Lee Irwin III To: Chris Friesen Cc: Mark Mielke , G?bor L?n?rt , Stuart Longland , Stephan von Krawczynski , Fabian.Frederick@prov-liege.be, linux-kernel@vger.kernel.org Subject: Re: 2.7 thoughts Message-ID: <20031010164408.GF727@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Chris Friesen , Mark Mielke , G?bor L?n?rt , Stuart Longland , Stephan von Krawczynski , Fabian.Frederick@prov-liege.be, linux-kernel@vger.kernel.org References: <20031009165723.43ae9cb5.skraw@ithnet.com> <3F864F82.4050509@longlandclan.hopto.org> <20031010125137.4080a13b.skraw@ithnet.com> <3F86BD0E.4060607@longlandclan.hopto.org> <20031010143529.GT5112@vega.digitel2002.hu> <20031010144723.GC727@holomorphy.com> <20031010144837.GB12134@mark.mielke.cc> <20031010150122.GD727@holomorphy.com> <20031010155007.GA13825@mark.mielke.cc> <3F86DFED.2030507@nortelnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3F86DFED.2030507@nortelnetworks.com> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mark Mielke wrote: >> Note that I didn't say that the software >> approach could *guarantee* immediate success. You wouldn't unplug the >> CPU until your had successfully deregistered the CPU from having anything >> scheduled for it. >> Is this not the way things (should) work? On Fri, Oct 10, 2003 at 12:35:57PM -0400, Chris Friesen wrote: > Note that if you're doing this for high availability purposes, you > already need to have some way of handling a cpu that just dies in the > middle of processing. Once you've done that, you can just re-use that > to handle hot removal--it just gets treated like a fault. This is not > to say that you can't try and shut it down nicely first, but its not a > hard requirement. If you've lost the registers in-kernel, you can't even get away with shooting the process. I'm not sure what extreme HA wants to do with that, but at a such a point it's not really even possible to figure out how to extract the thing from whatever critical section it may have been in. -- wli